1. Field of the Invention
The present invention is related to a method and a processor for image processing, and more particularly, to a method and an image processor for image dithering.
2. Description of the Prior Art
The bit numbers employed to express the respective pixels of an image, also known as the bit depth, determine the color depth of the image. In general, the visual quality of the image increases with the color depth.
The bit depth of the conventional display is limited, such as the computer monitor, the PDA display panel, and so forth. Conventionally, if the bit depth of the display is less than the color depth of the image to be displayed, then a technique is to be employed to display the image having more color depth on the display having less color depth. This technique, when applied to a display, is called dithering. For example, when a 6-bit display is utilized to display an 8-bit image, the dithering technique is employed to display the image having more color depth on the display with lower bit depth.
Before the display leaves the factory, the procedure of dithering of the display is determined and unchangeable. This means that the display processes all of the images according to the determined procedure of dithering. However, there is no procedure of dithering that is suitable for optimizing all kinds of images.